Janet Tweedy wrote:
Yes it does, you can search on each separate county.

www.ngs.org.uk/

These would be nicer gardens for a beginner as they are often slightly
smaller in size than the huge scale of NT ones, which might put off
someone who wanted to learn gradually

There's one open in Worthing by the Station, think it's the 23rd July
but there's a full list and details on the site.

Thanks Janet, and everyone else. I had a look at the website this
morning but couldn't find anything open today that was within a
reasonable distance. However, the weekend looks promising, and I think
you might be right about the smaller scale of the gardens :-)

Anyway, we ended up spending a few hours, and enjoying a pleasant lunch,
at West Dean, just a few miles up the road.

Brian